Then there is the equation.

x+y=20

x-y=3

The difference in area is x 2-y 2 = 20 * 3 = 60.

2. The original formula is simplified to 4ab, so the result must be even.

3. Let the middle number be a, then there is an equation.

a *(a+ 1)(a- 1)= a+a+ 1+a- 1

? Solution: a = 0；;

So these three consecutive integers are-1, 0, 1.